Messages in this thread | | | From | Liu Hua <> | Subject | [PATCH v2 0/2] change ARM linux memory layout to support 32 CPUs | Date | Fri, 11 Apr 2014 16:00:50 +0800 |
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Hi Nicolas or Russell,
This patch series change fixmap mapping region to suppport 32 CPUs. Because the "top_pmd" covers 0xfffe0000 - 0xffffffff(2M). And part is used by vector table. So I move this region down to 0xffc00000 - 0xffdffff.
I have tested the patches on arma9(2 CPUs) and arma15(16 CPUs) platforms
BTW, As we know we can configure NR_CPUS up to 32. So we need 2048K at most. But for ARM systems with less cpus, there is a waste of virtual address. So should we change its size according to NR_CPUS, as what MIPS linux does ?
Changes from v1: --------------- - changed documentation for ARM linux memory layout. - moved fixmap mapping region, not just extended.
Liu Hua (2): ARM : DMA : remove useless information about DMA ARM : extend fixmap mapping region to support 32 CPUs
Documentation/arm/memory.txt | 8 ++------ arch/arm/include/asm/fixmap.h | 4 ++-- arch/arm/include/asm/highmem.h | 1 + arch/arm/include/asm/memory.h | 2 -- arch/arm/mm/highmem.c | 10 +++++----- arch/arm/mm/mm.h | 7 +++++++ arch/arm/mm/mmu.c | 4 ++++ mm/highmem.c | 1 + 8 files changed, 22 insertions(+), 15 deletions(-)
-- 1.9.0
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